So I have a 75 gallon tank, no corals yet but it's going to eventually be a softy tank. Right now all I have is an aqueon 950 powerhead at the top middle on the side of the tank. It's kinda big and kinda ugly and it doesn't really give me the flow I'd like to see. I'm thinking of getting 4 hydor Koralia 425's since I can get a good deal on some but I don't know enough about flow to know if this is a good idea. Eventually I'd like to upgrade to a gyre xf350 but can't afford that for now. I was planning on putting them at the top in each corner pointing down the length of the tank to get good surface agitation and because I also read and saw a video showing how that created an effect similar to a gyre, just not exactly the same. Would this be too much flow? Not enough? Also how durable and long lasting are these pumps?